I had this same basic idea but tith Co2 Air cartriges for paint ball guns.

Also if you are wanting to use live ammunition, keep it low, like. 22 cal and the barrel would have to be metal. Grolly best to keep it down to the air cartriges cause using live ammo could yeild nasty results.

I think that a knife in the hands of the wrong person is much more dangerous then a machine gun in the right hands...I stupid girl almost took of my eye with a 6" model plane.She was lucky that my pneumatic wasn't charged and I'm a very responible gentleman.

omfg that's almost the same id of my full auto pneumatic/combustion concept `1hint don't do it!!!!!!!! if you add to much AP the gun could blow up in your face!!!!!!!!! you may be a gentleman but you never know. if i get you right you wanted to shoot @ a stupid girl with your pneumatic gun?? than you shouldn't make a full auto gun. because those things are always charged, and if the ammo isn't connected you should only need 10 sec.